The present invention relates to a packing box, and in particular to packaging box having a structure allowing no improper tear.
Generally, the structure of packaging box forms a body in a quadrangular cylindrical cardboard body with a front and back wall and a left and right side wall, and adopts basically a structure allowing openings, which are formed respectively at opposite top and bottom ends of the cylindrical body, to be opened and closed by folding the cover plate and bottom plate, which block off the openings, over the opposite top and bottom ends of the front wall.
Among these packaging boxes, particularly if the use is for holding medical supplies or the like, it is considered necessary to provide a function thereby making it impossible to rig a tear in order to prevent such risks as mischief or pilferage made against the contents.
For this purpose, pharmacists have added to the box structure of preventing tear or conversion. As the system that prevents an improper tear, it concentrates on the cover plate and base plate portion which can most easily be tricked for tearing.
The means which has heretofore been adopted for preventing improper tear and falsification, however, mostly adopts a double construction in the cover plate and base plate portion which would make it easy to detect a tear mark if the box should be torn, but the structure is complicated and inadvantageous for the manufacturing purpose, and it is a defect that a risk still remains for the contents which are possible to be taken out without giving any damage to the cover plate or base plate when they are torn carefully by means of a sharp knife or the like at the portion, for example, (overlap width), excluding the cover plate and base plate.
A packaging box provided with an improper tear prevention structure having the following construction was proposed by the inventor for solution of these defects as mentioned above:
(1) The cover and base plates, each with a foldably connected, adhesive tongue flap, are arranged connectively and foldably to lead respectively to the top and bottom of the back wall plate of the cylindrical box body so that the top and bottom opening surfaces can be blocked off.
(2) A uniform length of fold flap is arranged to lead connectively to the top and bottom of the front wall plate of the cylindrical box body, the said fold flap being folded inside the cylindrical box body so as to make a nearly adherent contact to the inner surface of the front wall plate.
(3) At folding section (the line bordering on the front wall) of the contact plate folded inside, a rib-tube opening is formed for inserting the adhesive tongue flap which is arranged to lead connectively to the tip of the cover plate or base plate.
(4) On the occasion of fabrication of the box body, the back of the adhesive tongue flap, which is arranged to lead connectively to the cover plate or base plate, is coated with adhesive (in the convention packaging box, the adhesive is coated on the surface of tongue flap), this adhesive coated surface being bonded with the inside of the fold flap located in the surface corresponding thereto.
(5) As a result that the back of tongue flap and the inside of the fold flap are bonded together, the adhesive coated surface becomes untouchable at all from the outside. This is the construction as referred to in the above.
In the case of the above mentioned construction, in the point that the improper tear can be prevented, it was remarkably superior to the conventional construction, while the fabrication of the box body requires a special kind of technology due to the complexities of the construction which is to be the other party to which the insert tongue flap arranged to lead connectively to the tip of the cover plate and base plate is recessed, i.e. the the complexities of the structure of the contact flap which was constructed so as to be arranged to lead connectively to the top and bottom of the front wall plate for being folded inside.